Marking on metal products. Marking methods.

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specializes in the design and supply of equipment for marking products of metallurgical plants.

Our engineers develop and implement specialized integrated solutions in metallurgy for marking both cold and hot metal.

Automated and automated systems allow for branding and marking of the following types of products: pipes, sheets, rolled products, coils, slabs, pigs, etc.

Our specialists also implement product identification and traceability systems throughout the entire production cycle of products, including the ability to transfer and use data at subsequent stages (storage, operation, etc.).

When designing systems, we use equipment from the world's leading manufacturers, which is optimally suited to the tasks of our Customers in each specific case.

Our engineers design and implement the following types of industrial marking solutions on cold and hot metal:

• Impact-mechanical marking and marking by drawing (using stamping)

• Marking with paint or ink

• Spray marking

• Laser marking

• Marking with plates (tags)

All solutions have the ability to program the composition of the brand, the ability to select font types and sizes using built-in control systems, and are also easily integrated with factory automated process control systems (APCS) - conveyor line control systems, etc.

Industrial markings in metallurgy are common and in many cases mandatory. Depending on the material on which the marking is applied and the requirements imposed by standards, technical specifications and customers, it is possible to use different types of marking of pipes, rolled products, sheets, coils, pigs, slabs, etc. Accordingly, different equipment is used to apply different types of markings .

Concept of labeling

Marking is the application of signs characterizing it to a product.

Methods of applying inscriptions on metal

This may include:

• Name,
• options,
• batch number,
• corporate logo,
• quality mark

The inscription should be clear, concise, and durable. Let's look at some ways of applying inscriptions to metal products.

Types and forms of brands

Precious jewelry is marked not only with gold hallmark numbers. All products must be branded. The applied mark may have a different shape, depending on the country of origin and the designation system adopted there.

In Russia, two types of printing are most often found:

• image of a female profile facing the right side;
• a hammer and sickle located on a five-pointed star.

Regardless of the shape and type, the mark must contain mandatory information: the code of the service that applied the seal, the marking of the content of precious metal in the alloy used and the symbol of the assay service’s identification.
The cost of products is directly proportional to the percentage of precious metal. It is almost impossible for a simple buyer who has no experience working with jewelry to determine the authenticity of the applied mark. Often very good and high-quality fakes with 585 or even 750 purity are passed off as real gold. In fact, scammers have learned to illegally apply samples and deceive consumers. To check whether the value of the mark corresponds to the true content of the precious metal, a visual inspection with magnifying devices and additional testing procedures will be required.

The surface of the gold object is first cleaned, then passed over the surface of a special stone. There should be gold stripes left on it, onto which you need to apply reagents. If the sample is high, then the remaining strokes will not disappear and will not even change color. If the strips have completely dissolved, it means that the product is of low quality or does not contain yellow metal at all. At home, it is extremely difficult to determine the quality of products , and it is not even always clear whether it is gold or silver. The 325th standard is the lowest that is allowed in jewelry production; it may outwardly look like a gold-plated silver product.

325 gold items are in demand and highly valued in England and some other countries. In Russia, this metal is considered low-grade. Separately, we can highlight jewelry with the designation 588. They are made of a high-quality alloy, including 11 parts of yellow metal and 1 part of elite platinum. The cost of such goods is much higher. Elite items also include items marked 983; their price can be extremely high due to the use of noble red gold.

Lettering methods

Branding methods can be different:

• Mechanical
• Chemical
• Electrical
• Photochemical
• Electrochemical

How to choose a labeling method? Usually the designer makes a choice by comparing some product parameters. Namely: product configuration, size, material, surface hardness, production volume, aesthetic requirements, the nature of the marking applied, its constancy, the degree of mechanization and automation of production.

Decoding of the name

1 - year code 2 - code of the State Inspectorate of Assay Supervision, in the area of ​​​​operation of which the manufacturer is located 3 - manufacturer code

breakdown by year: A - 2001, B - 2002, C - 2003, D - 2004, D - 2005, E - 2006, C - 2007, I - 2008

- the second indicates the inspection of the assay office: L - North-Western (no change)

— the last characters identify the manufacturer (without change)

As you can see, by the name and assay mark you can really find out what any product intended for sale in Russia is.

Electric spark pencil

Today you can find several names: electric pencil, electric spark pen, electric marker.

Electric spark pencil

Using an electric marker, inscriptions are applied to a smooth metal surface.

This method is chosen in cases where the impact-point method is not suitable, stamps are inconvenient, laser application is too expensive or impractical.

The marking pencil is mainly used for metal components and parts where bulging of the surface due to the marking is not allowed.

It is often used as a means of adjusting and correcting markings on a flat or relatively flat metal surface. The type and alloy of the metal may be different.

Stamps

For more accurate and convenient marking, stacked impact stamps are used. The necessary letters are inserted into the holder (punch), and the desired digital string is obtained. The line turns out smooth and uniform in depth. It is mainly used for marking relatively static data; it is inconvenient to enter serial numbers with such a device.

The kit includes Russian or Latin letters and numbers, special symbols required by the customer, etc.

Many self-respecting craftsmen, both in our time and in distant history, made homemade tools for their work. Previously, of course, it was not easy to get the necessary tools and even buy them, but today it would seem that there is nothing in specialized stores, and craftsmen still make their own tools, because it is cheap and simple.

Impact dot marking

The impact-point method is used for engraving on products made of soft metals. For example, such as brass, bronze, fittings. You can also order markings on metal for some piece products.

It is recommended to use for metal assembly units (assemblies) and parts, except thin-walled ones.

Impact dot marking

• With this equipment you can apply markings to any surface.
• This method is often used in the production of pipes and other metal structures.
• The main advantage of this method is the high speed of operation and the absence of consumables.
• The markings are clear. Has high resistance and durability.

Sets of letter and number stamps for metal.

In industry, there is often a need to apply certain information to surfaces with different properties. The simplest identification method for metal parts and workpieces is impact stamping. The method does not require expensive equipment and allows you to leave an indelible inscription in the form of deep, easily readable indentations: letters, numbers or the manufacturer’s logo. This could be a part identification code according to the assembly drawing, a serial number for maintaining special records, an element of a set of anti-counterfeiting measures, the passage of a released product through quality control, or individualization of the mechanism.

Laser marking

This marking method is represented by various devices. The following markers are possible:

• Gas laser
• Solid State
• Fiber optic markers for metal and plastic
• Lasers for delicate marking of electronics
• Ultraviolet for products in instrument making
• Double-headed devices for double efficiency

Many large enterprises in mechanical engineering, aircraft manufacturing, and instrument making give preference to this particular marking method.

What should the brand and name tag be?

The state assay mark is a special imprint that is applied by the state inspectorates of the assay supervision of the Russian Federation. It means that the product has been inspected by the inspectorate and has a grade not lower than that indicated in the stamp.

The state hallmark consists of an identification mark and an assay mark , which can be affixed together (in one image) or separately.

Since 1958, the ID badge has been an image of a hammer and sickle against the background of a five-pointed star. This sign is still in use today. Since 1994, an identification sign has been installed, representing a female head in a kokoshnik turned to the right in profile.

The hallmark is numbers showing the number of weight units of the precious metal in a thousand weight units of the alloy. If you see 925 purity, it means that there is 0.925 grams of pure silver per gram of the item.

The hallmark guarantees that the product has passed the test, and the content of precious metal in the alloy is not lower than the declared standard.

Electrochemical methods of marking on metal

Along with mechanical marking, electrochemical marking is also used - this is a technology for applying images, logos, alphanumeric information using electric current and acid.

Electrochemical marking

The operating principle is as follows. The power supply supplies electric current to the part through the electrode. The current, passing through the material soaked in the electrolyte and a special dielectric stencil for marking, leaves an etched mark in an empty space. It is necessary to ensure that the stencil fits tightly to the surface of the part to be marked.

The electrolyte for electrochemical marking is a saline solution that speeds up the process of transferring charged electrons between potentials.

The effective voltage for the etching reaction to occur is from 3 to 15 V. The peculiarity of this method of marking metal is that the boundaries are somewhat fuzzy. Therefore, the logo and details on it should be large enough.

Testing systems

In addition to the convenient and most accurate metric system, gold can be marked with a karat standard. This method of indicating the purity of an alloy is typical for America, Western Europe and some Eastern European countries. A carat is equal to 1/24 of the total mass, that is, 24 carat gold is a substance without impurities, and, for example, 18 carats means that the alloy contains 18 parts of gold out of 24. Common samples: 9, 10, 12, 14, 18 , 22 and 23 carats, the minimum permissible carat fineness is 8 carats. The ratio of carat and metric samples is as follows:

• 999 standard = 24 carats;
• 958 standard = 23 carats;
• 916 standard = 22 carats;
• 750 standard = 18 carats;
• 625 standard = 15 carats;
• 585 standard = 14 carats;
• 500 standard = 12 carats;
• 416 standard = 10 carats;
• 375 standard = 9 carats;
• 333 hallmark = 8 carats.

On products made abroad, for example, the following carat designations are found: 18K, 10Kt, 22CT, 12C. That is, one of the possible carat designations is placed next to the hallmark number in the stamp.

Convert carats to grams

The karat measurement of metals should not be confused with the designation of precious stones.
There the values ​​​​change, for example, 513 carats corresponds to a stone weighing 102.6 grams, 583 carats - 116.6 grams, 686 carats - 137.2 grams. The metric system determines the value of an alloy based on the gold content of 1 kg of the alloy. The most popular standard is 585, which means that per 1000 grams of alloy there are 585 grams of gold and 415 grams of impurities and other metals.

Since different countries have different systems, sometimes buyers get confused in determining the value of a product when choosing jewelry abroad. Gold hallmarks indicated in carats can be easily translated into understandable Russian numbers: 9 carats means a hallmark of 375 gold, 14 carats means 585, and 24 carats corresponds to the purest gold of 999 purity. For the manufacture of rings, 565 and 575 samples are most often used.

Stamps designate not only products made of gold, but also those made of silver and gilded. For example, a pure silver bar is 999 fine, but this composition is not suitable for making jewelry due to its softness and other physical properties. Household items correspond to hallmark 875, and jewelry - to 925. But gold rings, earrings and chains are not marked with hallmarks 593 and 725. Most likely, you got a fake, and you can determine this fact by contacting a pawnshop or buyers. They will evaluate the product.

How to determine gold purity by the color of the alloy

The color of pure gold is bright yellow, but due to its softness, this metal in its pure form is not used to create jewelry. Jewelry is made from gold alloys, in which only part of the composition is allocated to gold. Ligatures (additives) make the connection harder, stronger, and give it different shades.

Based on the shade of the alloy from which the product is made, one can assume its sample. But this method of determining the composition is imperfect; only examination can accurately determine the percentage of gold and other metals.

Pink

This shade is characteristic of alloys containing silver and copper, in particular the following samples:

• 375: dark pink,
• 585: soft pink;
• 750: slightly pinkish.

White

If you see a piece of jewelry with a white tint, most likely it is 750-grade metal. 25% of the composition is occupied by silver and palladium or silver and nickel.

Green

• Dark green color is typical for 750 standard with the following composition: 75% gold, 15% silver, 6% copper, 4% cadmium.
• The pale green material is obtained when 23% copper and 2% cadmium are added to 75% gold.
• The yellow-green metal is most likely 750 fine, and 25% of the composition is silver.

Violet

Gold jewelry may have a purple tint if it is made from a 14-karat alloy that contains 25% aluminum or potassium. If the color is rather bluish, then with a high probability it is a composition of 46% noble metal and 54% rhodium, cobalt or indium.

Sources

• https://lombardyinfo.ru/stati/probirnoe-klejmo.html
• https://ZolotoMan.ru/proby/klejmo-na-zolote.html
• https://ToZoloto.ru/proba/klejmo-na-zolote.html
• https://zolotogid.ru/metally/sistema-oboznacheniya-proby-na-zolotyh-izdeliyah-i-pozolote/
• https://uvelir.info/articles/probirovanie-yuvelirnyih-izdelij-eto-dolzhen-znat-kazhdyij-probyi-klejma-imenniki/
• https://goldomania.ru/articles-2/hallmark_gold.html
• https://russam.ru/stati/o_juvelirnyh_izdelijah/p18881-kakie_byvajut_proby_zolota/